Aun'Wei

Aun'Wei was Ethereal Supreme when the T'au still thought the galaxy was a timetable. His word launched the Second Sphere. After Damocles, an old Aun'Wei let his protege Aun'Va talk him into the Third, which is how a cautious empire became an aggressive one with better slogans.

When the Last Walk came he disappeared into a temple-dome the way Ethereals do, and Aun'Va took the title Master of the Undying Spirit. The Fire Caste remembers Wei as the elder who signed expansions. They do not remember him stopping any of them.

The Greater Good needed a first signature. Wei provided it. Va provided the hologram that outlasted a body.